Idaho Air Brakes Knowledge Test CDL Practice Test
Practice with real ID Air Brakes exam questions and detailed explanations. Rated 4.8 stars by 1,000+ drivers.
Written by CDL holders and exam prep experts · Updated April 2026
Free Questions
10
Passing Score
80%
Time Limit
Typically 30 minutes; varies by testing location
Prerequisites
General Knowledge test must be completed first
What is the Air Brakes Knowledge Test Test?
The Air Brakes knowledge test is required for commercial vehicles equipped with air brake systems. Passing this test demonstrates your knowledge of air brake operation, inspection procedures, and safety protocols, and removes the 'L' restriction from your CDL.
Knowledge test to remove 'L' restriction (no air brakes) from CDL
Topic Breakdown
Air Brake System Components
~8 questions
- Compressor and reservoir systems
- Brake chambers and slack adjusters
- Air lines and fittings
Inspection and Testing
~7 questions
- Pre-trip inspection procedures
- Air pressure tests
- Brake adjustment checks
Safe Driving Practices
~6 questions
- Proper braking techniques
- Following distance requirements
- Downhill braking procedures
Emergency Procedures
~4 questions
- Air pressure loss procedures
- Emergency braking systems
- Brake failure protocols
Free Practice Questions
10 questionsQuestion 1 of 10
Stab braking:
Browse Idaho Air Brakes Questions
- 1. Stab braking:
- 2. Parking or emergency brakes of trucks and buses can be legally held on by ____ pressure.
- 3. Which procedure is used for the spring brake test?
- 4. Characteristics of dual air brake systems include:
- 5. To check the free play of manual slack adjusters of S-cam brakes, you should park on:
- 6. Some air brake systems have an alcohol evaporator. What may happen if you don't keep the proper level of alcohol?
- 7. The most common type of foundation brake found on heavy vehicles is the:
- 8. Which procedure is used in controlled braking?
- 9. Which braking technique may be used to stop quickly when you do not have ABS?
- 10. A slack adjuster free play needs to be adjusted if it is more than about ____ when you pull hard on it.
Study Tips for Idaho
- 1Understand the air brake system components thoroughly
- 2Practice air pressure testing procedures
- 3Memorize safe following distances
- 4Know emergency braking procedures
- 5Review state air brake regulations and inspection requirements
Idaho CDL Information
Age Requirements
Intrastate: 18+ · Interstate: 21+
CDL Renewal
Every 4 years
ELDT Required
Yes — ELDT (Entry-Level Driver Training) from FMCSA-registered provider
Idaho Transportation Department (ITD)
Official CDL Portal →Career Opportunities
Frequently Asked Questions
If you plan to drive a commercial vehicle equipped with air brakes, you must pass the air brakes knowledge test to remove the 'L' restriction from your CDL.
Air Brakes Study Resources
Be Ready for Your Idaho Air Brakes Test
1,000+ drivers passed their CDL exam using CDL Answers.
Real questions. Detailed explanations. Know your score before test day.